It is known in the field to have electrical enclosures for use in poured concrete construction, and other forms of construction, where the electrical enclosures are put in place and connected to other electrical enclosures with electrical non-metallic tubing (ENT) prior to concrete being poured. Concrete is then poured to form the concrete walls of the structure, and, the concrete also forms around the electrical enclosure and the electrical non-metallic tubing (ENT). The electrical enclosures include electrical boxes, sometimes referred to as “electrical mud boxes”, and adapters therefor.
Typically, the concrete forms into which the concrete is poured may be several feet high, such as 6 to 10 feet high, representing the height of a concrete wall that is poured at any one time. For example, this may represent the concrete being poured for one level or floor in a building. Because of this height, and because of the density of the concrete, the poured concrete can develop significant hydraulic pressure. This hydraulic pressure acts on the sides of the electrical enclosure and may deflect the side walls of the electrical enclosures. Such a deflection can deform the electrical enclosure thereby limiting or inhibiting its use. Once an electrical enclosure is deflected such that an electrical device cannot fit within the opening, the box is generally no longer salvageable.
It is understood that once the concrete is formed, the electrical enclosure may be used to house switches, electrical receptacles and other components. The electrical enclosure may also be used to house or transport electrical cables or can be used simply as a junction box of various electrical cables travelling through electrical non-metallic tubing (ENT). The electrical enclosure may also be an adapter, such as an adapter to give a double electrical box a smaller opening, and, in this case it is appreciated that the dimensions of the adapter represent a principal characteristic of the enclosure.
In general, electrical enclosures are made of metals, or plastic materials, both of which are sturdy, but not necessarily intended to support large external forces. It is not unusual, because of the hydraulic pressure caused by both the height of the concrete walls, and also the density of the concrete, for the walls of the electrical enclosure to be deflected up to ⅛″ on both sides of the electrical enclosure causing a total deformation of up to ¼″. It is appreciated that as the electrical enclosure are deflected, their usefulness decreases as it may not be possible to insert the proper components into the electrical enclosure or the electrical enclosure may not be sufficiently large to permit the proper electrical components or cables to be properly housed. It is also appreciated that the proximity of various electrical components within an electrical enclosure is best not to be minimized.
Accordingly, there is a need in the art for an improved electrical enclosure for use with poured concrete, which prevents, or at least resists, deflection while concrete is poured so as to permit easy access to the cavity of the electrical enclosure after the concrete has cured and the forms have been removed.